Rotary dewaxer for coated paper or cardboard blanks



P. E. FISCHER July 1, 1958 ROTARY DEWAXER FOR COATED PAPER OR CARDBOARDBLANKS Filed March 3. 1955 5 Sheets-Sheet l July 1, 1958 P. E. FISCHER.2,841,112

ROTARY DEWAXER FOR COATED PAPER OR CARDBOARD 'Br-IKSV l Filed March 3,1955 l 5 SheeS-Shee'l'l 2 Arromv July l, 1958 Filed March 3, 1955 II LP. E. FISCHER ROTARY DEWAXER FOR COATED PAPER OR CARDBOARD BLANKSIIIIIIIIIIII I' FIIE.' E'

I I I I I I I I I I I INVENTOR P41/z. E Esci/Ei? ww/Ma July 1, 1958 P.E. FISCHER '2,841,112

ROTARY DEWXER FOR COATED PAPER OR ACARDBRD BLANKS Filed March 5, 1955 5Sheets-Sheet 4 INVENTo'R. P404 E. Fisc/,IER

BMWMW@ Juy 1, 1958 P. E. FISCHER l 2,841,112

ROTARY DEWAXER FOR COATED PAPER OR CARDBOARD BLANKS Filed March 5, 19555 Sheets-Sheet 5 50,4 50B sz E s PIE: z z

Arran/frs RTARY DEWAXER FR'CATED PAPER -OR CARDBARD BLANKS Paul E.Fischer, Minneapolis, Minn., assigner to E. G. Stande Manufacturingtompany, inc., Si. Pani, Minn., a corporation of New HampshireApplication March 3, 1955, Serial No. 491,875

5 Claims. ((1118-11) This invention relates to a machine for thedewaxing of selected areas only .of .coated paper or .cardboard blanksthat are used in the making .of boxes. `ln the packaging of modernmerchandise, particularly foodstuffs that are sold in a frozencondition, for the .preparation of milk cartons and many other types ofpackages, the package is made of a paper or cardboard material having onone or both surfaces thereof a coating which ,renders the cardboardimpervious orrelatively impervious to the passage of liquids or gasesthrough the box. Thecoating material is frequently paraihn but in manyinstances with the paraiiin there may be mixed other materials whichrender the coatings less pervious to the passage of moisture and gasestherethrough. Such additional materials which may .be combined with.paraiin, Vor used independently as a coating material may includesuchmaterials as microcrystalline waxes, plastic materialsand `the like.The coating of wax -or composition is applied .to the paper or cardboardsheet during the manufacture thereof and for the construction of the boxthere are then cut from continuous webs of the paper or cardboard,shapes of appropriate dimension and size, which when folded will formthe box that is desired. For brevity the paper or cardboard materialwill hereinafter be referred to as paperboard and thecutout patterns of-such material that are used for making the box will be referred to asbox blanks.

In the formation of the box, the box blanks .of paperboard are sentthrough box-forming machines, in which the box blanks are subjected tofolding operations and gluing operations for the purpose of making the.box shapes.

In this operation certain areas and tabs portions of Vthe box blanks arefolded into overlying relationship and are cemented to adjacent surfacesso as to form the box blanks. When boxes are made of uncoated materialthe adhesive that is used for thus cementing portions ofthe blanktogether will adhere tightly to the paper board but when wax or othercoating materials are applied to the paperboard, the adhesion of thepaste, glue or cement, however designated, is so greatly reduced as topreclude proper formation of the box. In order to overcome this difcultyit has heretofore been proposed that the wax or the like imperviouscoating should be removed from selected areas and various devices havebeen proposed and built for this purpose. Usually the removal of the waxis sought to be accomplished by applying heat to the surface of thepaperboard throughout the area-desired to be dewaxed. The apparatus foryaccomplishing this` function, heretofore availablehas not been-entirelysatisfactory.

It is an object of the present invention toprovide .an improvedbox-making apparatus and more particularly to provide an improvedmechanism for'removing from the surfaces of coated box blanks, the waxor the like coatings therefrom. It is a further object of the inventionto provide a dewaxing machine wherein the wax may be removed with greatrapidity and precision from cooperating st :faces of box blanks which itis desired ultitates Patent .mately to bring into juxtaposition foradhesive attachments may be controlled reliably with great precisionWithout the use of delicate apparatus. it is another object of theinvention to provide a dewaxing machine which is adaptable to thedewaxing of selected areas of a wide variety .of box blanks and can bemodified easiiy and quickly by the operator of the vbox-making machinefor accomplishing the dewaxing of different shaped blanks and differentsizes of box blanks. It is also an object of the invention to provide animproved rotary dewaxing mechanism which can be adapted to existingboxmaking machines without the addition of undue or cumbersomemechanisms. lt .is also an object of the invention to provide a rotarydewaxing drum of rugged construction capable of being manufactured atlow cost and used without interruption for long periods of service. Itis a further object of the invention to pro-vide an automatic andreliable control for the temperature of a dewaxing machine element.

Other and further objects of the invention are those inherent in theapparatus herein illustrated, described and claimed.

VThe invention is illustrated with reference to the drawings whereinFigures l, 2, 3 and 4 are diagrammatic schematic plan views of variousbox-making machine arrangements wherein the apparatus of the presentinvention maybe incorporated;

Figure 5 is a fragmentary plan view, much enlarged, of a representativeform of dewaxing apparatus of the present vinvention villustrating themanner in which the dewaxing elements are positioned for dewaxingportions of a particular representative box blank;

Figure 6 is an enlarged vertical sectional View of the dewaxingapparatus of the present invention, this figure being taken along theline and in the direction of arrows 6-6 of Figure 5;

Figure 7 is a fragmentary vertical transverse view, partly in sections,taken aiong the line and in the rection of arrows 7 7 of Figure 5;

Figure 8 is an enlarged vertical longitudinal secti view through theshaftl carrying one of the rotary d waxing elements of the presentinvention. Figure 8 is taken along the line and in the directions ofarrows of Figure ll;

Figures'9 and ldare enlarged fragmentary plan views of dewaxingelements, these figures being taken, respectively, along the line and inthe direction of arrows @ft-m9 and iii-10 of Figure 3;

Figure vll is an enlarged vertical scctionai view rotary dewaxingelement and backup wheel, this vin in g .taken along the line and in thedirection of 11-11 of Figures 6 and 8;

Figure l2 is a plan view of an exemplary form mon box blanks such as maybe dewaxed prepara box formation by the apparatus of the proscrit i.tion;

Figure 13 is a graph representing the form of cycles for operation ofthe electric heaters of the nuxremoving devices used according to thepresent invention.

Throughout the drawings vcorresponding numerals refer to the same parts.

The apparatus of the present invention may be used as a separate entity,in which case the already cut b x blanks are Vfed to it and dewaxed bythe machine and then stacked. For use in thismanner the dewaxer element,shown generally at .ad in Fig. l, is incorporated in a machine with afeeder '11, which may be of any construction, known inthe art, and witha device known as a stacker, shown at l2 in Fig. l, by means of whichthe box blanks are stacked or otherwise arranged in orderly manner foryconveying from the machine. In such an arrangement the feeder 1l,vdewaxer itl, and stacker i2, constitute the entire device. The presentinvention is directed to that portion lil, namely the dewaxer, as shownin this figure. 'Y

More usually, however, the dewaxer apparatus of the present inventionmay be utilized as one working stage in a box-forming machine, thus asshown in Figures 2, 3 and 4, there are shown representative types ofbox-forming machines which are however modified to include the presentinvention. Thus, in Figure 2 is shown a feeder ll, a de-waxer stationl0, and remaining box-forming stations of the machine Which include aiirst folder i3, second folder 14, gluer l5, and a delivery conveyor 16.lt is one of the advantages of the present invention that it may thus beincorporated in the usual box-making machine since by so doing the boxblanks which have selected areas thereof dewaxed, are carriedimmediately through the machine and without such dewaxed portionsappreciably cooling are immediately carried through the appropriatefolding stages and gluer stage, thus completing final box formation.This is a distinct advantage since in the gluer, the adhesive materialwill more readily stick to and bite into the still hot dewaxed areasthan would be the case if the dewaxed box blanks were stacked andpermitted to cool. I have observed that this phenomenon is particularlytrue when the box blanks are coated with those modern coatings which arecomposed of plastic compositions, alone or plastic in admixture withwaxes of various types. It is therefore a feature of the presentinvention that the dewaxer is incorporated as one stage in a standardbox-making machine and that the blanks are fed through the machine withsuicient rapidity that they do not appreciably cool before the glue isapplied to the selected dewaxed areas, thereby increasing the adhesivepower of the glue for holding the box in its completed form.

In Figure 3 there is illustrated another typical boxmaking machine towhich there is added a dewaxer stage, according to the presentinvention. Thus, in the Figure 3 machine there is provided a feeder 11,a dewaxer l0, prefolder 17, gluer 18, and delivery conveyor 19.Similarly in Figure 4 there is illustrated a box-making machine whereinthe travel of the box blanks is along an L-s'hape or right angular path.In this machine there is illustrated a feeder l1, a dewaxer l0, afirst-fold 2t), a transfer table 2i, gluer 22, and delivery conveyor 23.

Thus, according to the present invention, the dewaxing mechanism may beincorporated in a complete boxmaking machine to the end that the boxblanks, on which selected portions of the wax coating have been removed,are caused to move with such great rapidity and are glued and folded tocomplete the final box formation before the surfaces from which the waxhas been removed and which are heated during such removal, haveappreciably cooled.

in order to accomplish the wax removal with rapidity and precision thereis according to the present invention utilized a rotary heated wheelhaving pads of appropriate shape on the periphery thereof which are runinto contact with the blanks, `the blank being meanwhile held by abackup wheel. The path and movement of the blank is timed in synchronismwith the rotation of the heated wheel carrying the heated pads, and aback-up roller is provided so that the blank is pressed tightly againstthe heated pad as the roller carrying the pad moves peripherally. Y

Thus referring to Figures 5-11, at each stage of the machine where aselected portion of the box blank is to be dewaxed, there is provided aheated roller and back-up roller. Referring to Figure 12, there is showna representative form of common box blanks at B. The box blank isprogressed through the machine in the direction of arrow 24. This blankis of standard form for making a tray-like carton with folded cover,suitable for the packaging of frozen or similar foods. For attaching thevarious portions of the blank together, adhesive is applied to thoseupper surfaces denoted Ul, U2, U3, U4, U5 and U6. Likewise there are onthe bottom surface of the blank B co-operating areas which willV befolded against the upper areas U1 through U6. These lower surface areasare shown in the box blank l2 at Bl, B2, B3, B4, B5 and B6. The boxblank B is shown in Figure 5 as being carried along a path of motion 24through the machine. The box blank is carried by a pair of roller chains26-27 having upstanding iingers 26A and 27A thereon which engage theback edge of the blank B and hold it in a certain position withreference to the chains .M -27. The chains 26-27 move through themachine by virtue of gearing and mechanism not illustrated which isdriven from, for example, a drive shaft 2S, at the side of the machine,through the gear box 2.9. According to the present invention, the samedrive shaft 23 andrgear box 29, or other gear boxes and drive shaftswhich may be provided on the machine and run in synchronism with 28-29,are utilized for synchronously rotating certain rotary cross shaftswhich extend from one side frame member of the machine to the other.Thus, in Figure 5 there are provided side frames 30 and 31 which are themain side frames of the machine and these are supported in properrelation by transverse members 32, 33 and other members throughout themachine. Suitably journaled in appropriate bearings on the side framemembers are the cross shafts 34, 35, 36, 37, 38 and 39, see Figure 6.Three pairs of cross shafts are usually sumcient for dewaxing the areasof any normal box but it will be understood that it is within the scopeof the present invention to provide a greater or lesser number of pairsof cross shafts. As shown in Figure 6, the three pairs ofcross shaftsare arranged as vertically spaced pairs, thus shafts 34 and 3S form apair, 36 and 37 form a pair, and 3S and 39 form a pair. The rotation ofthe pairs of shafts is as shown by the arrows thereon and each of theshafts is driven, as by the drive gears 34A, 35A and 38A shown in Figure5, so that all run at the same speed and in timed relation, in respectto the movement of chains 26-27- The rate of rotation of the shafts issuch that a back-up roller and heated pad, of a given equal radius, willhave a peripheral speedrequal to the linear speed of the chains 26 and27. For convenience all of the rotary back-up rollers that are utilizedare the same diameter and the heated pads are segments of a circular rimwhich has a radius from its mounting shaft precisely equalling that ofthe back-up roller. By this means it is therefore feasible tointerchange the rotary pads on their rotary hubs, and to interchange theback-up rollers as desired. The rotary pads and back-up rollers arearranged in pairs and, as all are identical, only one pair need bedescribed in detail.

Thus referring to Figures 7 through ll particularly, there isillustrated one rotary dewaxing wheel and pad, where the wheel is abovethe rotary back-up roller. This may be assumed to be the mechanism shownat position 4t) of Figures 5 and 6. At this position the upper shaft 34is provided with a heated roller generally designated 42, andco-operating lower shaft 35 is provided with a back-up roller generallydesignated 44. Each of the shafts is keyed so that the heated roller 42and back-up roller 44 rotate with the shaft, without turning. Theserollers may be shifted along the shaft for adjustment transversely ofthe machine. The radius of the heated roller 42 as measured to the outersurface of the heated pad 93 thereon is precisely equal to the radius Rof the back-up roller 44.

The heatedroller 42 consists of a hub 46 which is keyed at 47 to theshaft 34. The hub is provided with a shoulder portion 48, forming asurface at 49. Around the hub there is positioned a tire Sti having abore of radius R2, which is considerably larger than the radius andiniaRl of the hub. There accordingly is provided a space at 52. in order tosupport the tire 50 concentrically with the hub there are provided ateach side of the assembly a plurality of metallic and insulating rings.Thus there may be provided metallic rings at 53 on the left side of thehub as shown in Figure ll and metallic rings at 54 at the right side.interleaved between the metallic rings are rings of insulating materialsuch as asbestos. The insulating rings are shown at 55 to the left inFigure ll and at 56 to the right in Figure ll. In order to hold themetallic and insulating rings in place, there are provided a pluralityof screws at 57-57 at the left and at 58 on the right. These screws holdthe inner and outer edges of the rings to the hub and tire respectively.rthe inner set of screws at the right side shown in Figure ll, areextended outwardly as at d and serve to secure in place an outer collar5? which is provided with a set screw at d@ by means of which the key 47may be secured, and the entire assembly 42 kept from shifting axially onthe shaft The collar 59 also serves as a mounting place for a terminalcollar 6i which is insulated by an insulating ring 62.

The tire Sti is a casting and in it is cast an armored electrical heaterelement 6d which extends around the periphery of the tire through two ormore turns, or as rnany turns as needed for distributing the heat of theelement to the tire. he electrical heating element has inlternedterminals at e5 and 66, the terminals being in the space 52. From theterminals extend connecting wires 66 and 67 which pass out throughapertures through the set of rings, 5d and 56 and extend to and aremounted on terminal studs 63 and 69 on the insulating terminal collar6i. From the studs 63 and 69, which are therefore electricalconnections, there extends a iiexible cord fd which wraps around theshaft .3i-'i in one or more turns and terminates at slip rings '71, seeFigure 7. ri`he slip rings 7i are of standard construction, two innumber, and are mounted upon an insulating collar 72 which is arrangedwith a set screw at 73 so that it likewise may be mounted to turn uponthe shaft 3d, or shifted along the shaft for adjustment purposes.Cooperating with the slip rings is a brush holder bracket assemblygenerally designated 7S, see Figures 6 and 7. For each assembly composedof a heated wheel 42, slip rings 7l there is also provided a brushholder of the type shown at 75. The brush holder is of standardconstruction (save for mounting) and has a pair of brushes at 76, seeFigure 7, and these are mounted in insulated relationship on a metallicbracket 77, which is provided with a terminal at 7d into which anelectrical connection plug 79 may be attached. The plug 79 is connectedthrough a cord Sii to a control box 8l, the function of which will bedescribed. For each of the pairs of shafts 34-35, there are providedsupports for the brush holder assemblies for both the upper shaftposition 34 and the lower shaft position 35. Thus allowing shifting ofthe brush holder to serve the heated roller whether the latter bemounted on upper shaft 34 or lower shaft 35. The upper support consistsof a member 8.?. having a V-way channel S3 extending thereacross intowhich the dovetail 84 of the brush holder frame 77' is adapted to beattached. The brush holder may be provided at Sd with a locking nut tohold the brush holder against transverse displacement once it isadjusted to the proper position in way 83. The way 83 extends entirelyacross the width of the box-making machine and the brush holder maytherefore be adjusted to any position. The reason for this is that therotary dewaxer may be desired to be displaced axially in respect to theshaft 3d to any position across the width of the machine and the brushholder is correspondingly displaced along with the slip ring. it will benoted that the brush holder is also provided with an aperture at 86 anda clamping block 37 held in place by cap screws. This form of mountingis utilized when the brush holder is placed in a position such as toserve slip r-ings located on the shaft 35. This position is showngenerally at 8S, adjacent to shaft 35. It will be noted that at locationS9, see Figure 5, there is a back-up roller on the upper shaft 3d andbelow it is a heated dewaxing roller` Such dewaxing roller is served bythe brush at position 38. The brush holder at position 88 is mountedupon a transverse rod 97 ex-tending from one side frame member toanother. The brush holder is held in any adjusted position by tighteningdown t-he clamping block 87 by means of the screws 9u 9d.

Referring again to Figure 1l, the tire 5d, is thus heated by the cast inheating element 64 and the outer surface SGA of the tire accordinglybecomes very hot. This outer surface is provided with spaced sets ofdrilled and tapped holes SdB at 20 intervals around the circumference ofthe roller. To these tapped holes there are attached pads which do theactual dewaxing operation. These pads are best illustrated in Figures 8through ll. Thus referring to Figure 8 there are provided two oppositelydisposed pads generally designated 92 and A?. These pads are ofidentical pattern and have an inner concentric flange portion 92A and acentral land 92B, for the pad 92 and a iiange 93A and land 93B for thepad 9.3. The lands 92B and 93B are cut so as, when rotated into contactwith the blank, they will print (or cover) the space on which it isdesired to place glue, for example, pattern as shown in Figures 9 andl0. These are representative of customary areas, such as the areas U5and U6 of Figure l2, or B5 and B6 of Figure l2, which may be desired tobe dewaxed. The lands are shaped appropriately in dimension and contourand since they are mounted upon the tires Si) of the wheels 42, and theentire assembly 42 of the dewaxer rotates in harmony and synchronismwith the movement of the blani; B, adjustment may be made so thatselected areas, accurately located dimensionally in respect to the blankB, may be dewaxed. For accomplishing such an adjustment, the lands mustbe placed at appropriate intervals around the periphery of the tire Sd,and the wheel t2 must be adjusted transversely of the machine, on shaft3d, so as to bring the land against the precise portion of the blank Bwhich it is desired to dewax, as the blank passes between the land andthe back-up roller d4, as shown in Figure 8. In some instances, as whereexceedingly large boxes are being made, only one such pad 912 or canmounted upon the roller 42 but in the usual small box, several lands can'be mounted, positioned and adjusted so as to dewax a pair ofcooperating areas for each rotation of the wheel 42.

To sum up therefore, at each of the dewaxing stations, represented bythe station in Figure 5, or the station Si?, or for any of the stationsthat may be desired to be provided on shafts 34 to 39, there is a ipairof cooperating rollers; one a heated roller as at $2 `and the other aback-up roller as at and such heated roller is provided with electricalpower supply through a slip ring and brush assembly as shown in Figure 7from a control box generally designated 31.

'Referring to Figure 5 there is shown at location a lower dewaxingroller and cooperating upper back-up roller. The lower dewaxing rolleris served by the brush holder and slip ring assembly 101 from anelectrical control box lZ which is identical with the control box Siserving position 40. Similarly at location 104 in Figure 5, there is apair of composed of an upper dewaxing roller and a lower back-up rollerserved by a brush holder and slip ring assembly HES from the control box105. Similarly at location idg on shaft 38 there is a heated dewaxingroller on the upper shaft and a cooperating back-up roller on the vlowershaft, which is shaft 59, thc heated roller being served to the slipring and brush assembly idg from the electrical control box iii?.Accordingly, as many rollers may be used as desired and these may beadjusted in position `along the length of any of their respective shafts34 through 39. ri`he heated rollers are provided with pads ofappropriate shape, dimension and position, and they are adjusted to takeolf the wax of selected areas of any box blank within the capacity ofthe machine.

For controlling the degree of heat of the dewaxing rollers there is,according to the present invention, used the following system: Each ofthe identical control boxes 81, 87, 102, 166 and 110 (or as many asthere are used), individually serves a certain heated dewaxing roller ofthe type at 42 in Figure l1, as described. The heat input to thedewaxing roller must be varied according to the ambient temperature, theamount of Wax which is removed, the rate at Ywhich blanks are fedthrough the machine, and the heat of vaporization of the wax itself.These many variables require a relatively wide range of heat input tothe rollers, and provision must therefore be made for varying the Iheatinput, to the end that the temperature of the heated pads 92 and 93, oneach of the rollers 42, may be maintained sufficiently hot so asadequately to vaporize the wax coating, but without getting so hot as toburn or Scorch the paperboard. To accomplish this Vfunction according tothe present invention, thereis provided an electrical timer switchmechanism in the box 81 and a similar timer mechanism in all of theother identical controls 87, 102, 1.06 and 11b enumerated. This timermechanism is, per se, of standard form and operates on a continuouscycle of relatively short duration, such as a 30-second cycle. Theparticular cycle duration which is chosen is not of extreme importance,the only requirement beingV that it be repeated with reasonablefrequency, preferably at less than l-rninute intervals. The timermechanism,rsuch as 81, which in itself forms no part of the presentinvention except as it is a component in the organization, is of a typesuch that a circuit is closed at the beginning of the cycle andmaintained closed for a certain portion of the cycle which may be variedfrom of the cycle up to 100% of the cycle. Thus referring to Figure 13,there is illustrated the operation of the timing mechanism.

It may be assumed that the time cycle has a time durai tion of 30 units,as for example 30 second, denoted by the dimension C on the time scale.The total length of the time cycle may be from a fraction of a second upto several minutes. Thus, where a machine may process several hundredsof box blanks per minute, the timer may have a total cycle length asshort or even shorter than thev time for processing one blank up to andeven ylonger than the time for processing several hundred blanks. At thebeginning of each cycle, as at time O seconds, 30 seconds, 60 secondsand 9() seconds, the circuit is closed by the timing mechanism and thecircuit remains closed during the on period. The circuit is then openedfor the balance of the cycle, as shown by the dimension off For theyirst two cycle positions as shown at Cl. and C2, the circuit isadjusted to remain closed; for example, 2O seconds out of 30 seconds,the balance, or seconds, being off The machine may run continuously forlong periods with such a division of the on and olff portions of thecycle. The heat capacity of the tire 5G and the pads 92 and 93 thereonserves to average out the temperature, which-accordingly will varyrelatively slowly as adjustments of the timers 31 etc. are made fromtime to time, and as the heat Iconsuming conditions vary. lf the boxblanks become Voverheated (and this condition is readily indicated by aslight darkening of the dewaxed surface), the temperature may be reducedby the operator for any of the dewaxing stations, by merely changing theadjustment of the timer by means of dial 81A. A corresponding timeradjustment of any of the other units so as to decrease the on andincrease the off portion of the cycle `may be made. Such an adjustmentis indicated as at C3 and C4 in Figure 13, where the timer for the onportion has been decreased to approximately 18 seconds and tie olfportion of the cycle increased correspondingly to approximately 12seconds. Accordingly, by turning the heating element d2 on and offrepeatedly, once for each cycle, and by usingV cycles of short duration,one is able accurately to adjust the temperature of the dewaxing wheelft2. The operator may individually control the temperatures of each ofthe rotary dewaxing stations, since the heat loads on all may not beequal. Since the timers Si are of standard construction, easilymanufactured and low in cost, and yet of rugged and reliable operatingcharacteristics, they may be used for long periods without difculty.

Each of the timers at 31;, S7, MP2, lilo, and il@ is mounted on thecross rails SZ at the appropriate stations, by means of a clamping boltat i2@ and each timer is served by a power input lead 112i from supplyboxes 22 on the sides of the machine Vframe.

Many variations may be made in the details of the present inventionwithout departing from the spirit 'and scope thereof and the specificdevices herein shown and described must therefore be considered only asillustrative of the invention and not as limitations thereon.

vWhat i claim is:

1. A machine for dewaxing selected portions of the surface of wax-coatedbox blanks comprising a frame, a power drive on the frame, box blankcarrier means connected to said power drive and mounted on the frame forcarrying said blanks along a straight plane of movement at apredetermined speed and in succession, at least one pair of cross shaftsextending across the machine at equal distances above and. below theplane of movement of said box blanks, said shafts being connected to thepower drive so as to be driven thereby in synchronisrn with said boxblank carrier means, heated roller means mounted on one of said shafts,said roller means having a pad on the periphery thereof forming acircumferential surface thereof, said pad being shaped to correspond tothe area of the box blank which it is desired to dewax, and Ysupportroller means on the other shafts having a diameter such that it willhold the box blank against said pad as the blank is moved therebetween.

2. in a rotary dewaxer for dewaxing selected areas of box blanks, a pairof wheels for rolling engagement of the outer peripheries thereof, saidpair being composed of a back-up roller having a continuous outerperiphery and an impression wheel comprising a hub and a tire attachedto said hub and Vthermally insulated therefrom, said impression wheelhaving the outer periphery of its tire interrupted to provide at leastone raised portion with a selected area of engagement against saidback-up roller, said impression Wheel tire having substantial heatcapacity and said raised portion having relatively small heat capacitycompared thereto, said impression wheel being provided with an electricheater for the tire thereof for heating said raised portion, an electriccircuit including a slip-ring and brush assembly for energizing theelectric heater as the impression wheel rotates, means for moving boxblanks in synchronism with and in adjusted position between the wheelsas they rotate for engagement of the impression wheel raised portionwith the correspending selected area of each box blank, and means forcontrolling the amount of electrical energy supplied to said heater,whereby said thermally insulated impression wheel tire of comparativelylarge heat capacity tends to stabilize the temperature of saidimpression wheel raised portion and prevent rapid temperature changesthereof.

3. A dewaxing assembly for dewaxing selected areas of box blankscomprising a back-up roller having an outer periphery of uniform widthand an impression roller having a tire thermally insulated from the hubthereof, said impression roller tire being provided with at least onedetachable pad extending radially outwardly therefrom and forming aperipheral surface forrolling contact with the outer periphery of saidback-up roller, said pad being inV thermal contact with said tire, saidtire having a substantially greater heat capacity than the heat capacityof said pad, a pair of shafts for mounting said rollers in a positionsuch that the periphery of the backup roller and the peripheral surfaceof the pad portieri on said tire will roll in contact with oppositesides of a box blank which is moved edgewise between them, an electricheater mounted on the tire of said impression roller, and an electriccircuit including slip rings and cooperating brushes for communicatingelectric power to the electric heater, whereby said thermally insulatedimpression roller tire of comparatively large heat capacity tends tostabilize the temperature of said pad and pre rapid temperature changesthereof.

4, A dewaxer wheel assembly in a box blank dewaxing machine comprising ashaft rotatably mounted in said machine, a hub fixed to said shaft forrotation therewith, a tire of larger internal diameter than the outerdiameter of said hub mounted on said hub by a rigid thermally insulatedconnection extending outwardly from said hub, a dewaxer pad detachablymounted on the outer surface of said tire in intimate thermal contacttherewith, said pad being shaped to correspond to the area of the boxblank which it is desired to dewax, said tire extendingr continuouslyaround said hub and having substantially greater heat capacity than saidpad, said tire being provided with an electric heater, and electricalconnections including a slip-ring and brush assembly connecting saidheater with a source of electrical energy for heating said tire, wherebywhen said heater is supplied with electrical 10 energy said tire ofsubstantially greater heat capacity will heat said dewaxer pad andminimize temperature fluctuations therein without conducting anysubstantial amount of heat to said hub, shaft, and machine.

5. A dewaxer wheel assembly in a box making machine comprising a hubhaving means thereon for detachably securing it at varying places alonga shaft for rotation with said shaft, a heavy tire of larger internaldiameter than said shaft, a heat insulating connection between the tireand hub for mounting the tire in spaced rention concentrically with thehub, said tire being provided with an electrical heater, a terminalblock m-ounted on said shaft, and electrical connections between theheater and said terminal block, said heat insulating connectioncomprising thin rings of metal and rings of heat insulationtherebetween, said rings being secured respectively to said hub andtire.

References Cited in the tile of this patent UNITED STATES PATENTS1,505,227 Staude Aug. 19, 1924 1,541,600 Steenstrup June 9, 19252,115,283 Potdevin Apr. 26, 1938 2,194,587 Brown et al Mar. 26, 19402,357,845 Nordquist Sept. 12, 1944 2,602,416 Perilli July 8, 1952

